Concrete grinders are used for grinding concrete and asphalt surfaces to remove irregularities in the road surface, to provide texture to the surface to prevent skidding. Grinding and texturing are used on concrete surfaces including roads and streets, airport runways and bridge decks, industrial plants, stock pens and barns. The diamond tip blades that are used to grind the concrete or asphalt surfaces are mounted on a rotating arbor. Typical grinding machines have the arbor mounted on an under carriage so that both ends of the arbor are supported by bearing assemblies capable of sufficiently supporting the arbor while enduring the high stresses associated with concrete grinding. Such grinders are large, heavy machines with sufficient mass to impart the high forces necessary for effective concrete grinding.
Smaller concrete saws are utilized to maintain expansion joints in the roadway and to separate damaged sections of concrete for easy removal. Such saws typically have a narrow cut and do not have sufficient power or mass for concrete grinding. Other specialized grinders are used to create slots for reflectors or to create rumble strips.
An example grinder is shown in U.S. Pat. No. 4,516,808 assigned to MU, Inc. As referenced in that disclosure, “when a paved surface is being ground, it is usually necessary to make more than one pass across the surface with the grinding units. It is a constant problem to insure that the grinding depth of the grinding unit is adjusted so that side-by-side grinding paths in the paved surface are level at the intersection of the two paths.”
Another example grinder is shown in U.S. Pat. No. 5,161,910, assigned to Diamond Surface, Inc. As referenced in that disclosure, “the power supplied from the mechanical drive limits the torque supplied to the arbor. The width of the arbor cutting surface is then limited as greater power is required as more blades are added for a longer cutting surface. Because of power considerations, grinders have heretofore been limited to arbors having a three foot cutting width. The width of the cutting path affects the time required to perform the grinding or grooving work. When grinding and grooving are performed, adjoining cuts must be precisely aligned to ensure proper cutting depth and an even pavement surface. The alignment process for each pass and added cutting passes due to narrower cutting heads greatly increase the time required for grinding.”
A further example grinder is shown in U.S. Pat. Appln. No. 2010/0109421, also assigned to Diamond Surface, Inc. As recited in that patent, “a grinding assembly may take the form of grooving blades, a single blade for cutting slots in the pavement, or other configurations with radial blades that require cooling and/or dust control. In many conventional configurations, the arbor may take on a variety of typical widths, generally extending from 2-4 feet.”
These above grinding and cutting devices are not suited for performing certain grinding functions.